• Title/Summary/Keyword: Post-selection

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A Study on the Site Selection of Unmanned Post Office Considering the Operation Cost by the Mail Volume (우편물량 규모에 따른 운영비용 기준의 무인화 대상우체국 선정에 관한 연구)

  • Choi, Jiyoung;Lee, Jeong-hun
    • Korean Management Science Review
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    • v.33 no.3
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    • pp.1-18
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    • 2016
  • Recently, ordinary mail is decreasing continuously by the development of ICT (Information and Communications Technology) including E-mail, messenger service, and etc. On the contrary, parcel post is increasing by the increase of online shopping, home shopping, and etc. Aside from these changes, the demand for various mail acceptance and delivery means is increasing with the increase of single households and dual-income couples. To overcome these environmental changes, Korea Post installs unmanned post offices which are composed of various unmanned mail acceptance and delivery postal systems. In this paper, we propose the methodological approach for the site selection of unmanned post office among the existing post offices and the installation standard of unmanned postal system considering the operation cost by the mail volume.

Weak Value Measurement of an Optical Beam Deflection in Image Rotating Sagnac Interferometer

  • Park, Sang-Joon;Kim, Hyoung Joo;Noh, Jaewoo
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.277-281
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    • 2012
  • We measured small optical beam deflection in an image rotating Sagnac interferometer. We used a weak value measurement scheme that involves a pre-selection, weak perturbation, and a post-selection procedure to obtain the amplified value of beam deflection. The amplification factor of the measured beam deflection varied from 11 to 63 depending on the settings of the post-selection polarizer in front of the photodetector and the settings of polarization compensator in the interferometer.

Permutation test for a post selection inference of the FLSA (순열검정을 이용한 FLSA의 사후추론)

  • Choi, Jieun;Son, Won
    • The Korean Journal of Applied Statistics
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    • v.34 no.6
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    • pp.863-874
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    • 2021
  • In this paper, we propose a post-selection inference procedure for the fused lasso signal approximator (FLSA). The FLSA finds underlying sparse piecewise constant mean structure by applying total variation (TV) semi-norm as a penalty term. However, it is widely known that this convex relaxation can cause asymptotic inconsistency in change points detection. As a result, there can remain false change points even though we try to find the best subset of change points via a tuning procedure. To remove these false change points, we propose a post-selection inference for the FLSA. The proposed procedure applies a permutation test based on CUSUM statistic. Our post-selection inference procedure is an extension of the permutation test of Antoch and Hušková (2001) which deals with single change point problems, to multiple change points detection problems in combination with the FLSA. Numerical study results show that the proposed procedure is better than naïve z-tests and tests based on the limiting distribution of CUSUM statistics.

A Study on the Selection Behavior and the Post-purchase Satisfaction for Men's Suits (남성 정장의 선택행동 및 구매 후 만족도)

  • Park, Young-Hee
    • Fashion & Textile Research Journal
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    • v.12 no.1
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    • pp.46-59
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    • 2010
  • This study is a survey research for adult men in their from 20's to 50's. The purpose of this study is to find out that demographic characteristic, material knowledge, and purchase price have what effect on the selection behavior and the post-purchase satisfaction. The results are as follows. The purchase place according to demographic characteristic showed the significant difference in ages, monthly income, and occupation. The purchase amount per a dress suit and the having quantity of dress suits showed the significant difference according to all demographic characteristics. The importance of an selective criteria in case of selecting dress suits showed the partly significant difference according to demographic characteristics. The post-purchase satisfaction showed the no significant difference according to demographic characteristics, but showed the significant difference according to the knowledge degree for materials and purchase amounts. The interaction effect among demographic characteristics, the degree of knowledge for materials, and the purchase amount showed frequently the significant difference between two variables. The factor which have most greatly an effect on post-purchase satisfaction of menswear was the degree of knowledge for materials.

Empirical Evidence of the Interdependence of Retirement and Pre- and Post-retirement Consumption (은퇴 결정과 은퇴 전·후 소비의 상호작용)

  • An, Chong-Bum;Jeon, Seung-Hoon
    • Journal of Labour Economics
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    • v.27 no.3
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    • pp.1-23
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    • 2004
  • To investigate the interdependence of the decisions on when to retire and how much consume before and after retirement, we compare the pre- (or post-) retirement consumption conditioned on the retirement decision with pre- (or post-) retirement consumption regardless of retirement decision by using the Korea Labor and Income Panel Study(KLIPS). We employ the two-stage switching regression for the econometric method to investigate the interdependence of two decisions of retirement and pre- or post retirement consumption. Then we test the existence of the interdependence in terms of the significance of the estimated selection biases which appear in the pre- (post-) retirement consumption equations for early and late retirees. In those equations, we also compare the income elasticity of the consumption of the early retirees with that of the late retirees. The empirical results show that there is negative selection bias in early retirees' consumption. These results imply that due to the early retirement decision early retirees would have consumed less than they actually have. The income elasticities of the consumption of the early retirees is smaller than that of the late retirees in pre- (or post-) retirement consumption equation. This result shows that relatively longer retirement period due 10 the early retirement affect the pre-retirement consumption. early retirees' marginal propensity to consume should be lower than that of the late retirees.

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Effects of Food Selection Attribute on Post-purchase Consumer Behavior in Big Discount Stores (대형 할인점에서 식품 선택 속성이 소비자의 구매 후 행동에 미치는 영향)

  • Jung, Gi-Jin
    • Culinary science and hospitality research
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    • v.15 no.3
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    • pp.248-261
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    • 2009
  • The purpose of this study is to examine the effects of selection attribute in big discount stores upon post-purchase consumer behavior and provide reference materials required for big discount stores to develop customer satisfaction strategies. As a result, this study shows the following findings: First, product-related factors had positive effects on post-purchase consumer behavior. Second, service-related factors had positive effects on post-purchase consumer behavior. Third, store-related factors had positive effects on post-purchase consumer behavior. Conclusively, it is advisable that big discount stores provide a variety of personalized services for customers to create and attract their trust, motivating effective recommendation to their acquaintances.

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Incremental Antenna Selection Based on Lattice-Reduction for Spatial Multiplexing MIMO Systems

  • Kim, Sangchoon
    • Journal of Advanced Information Technology and Convergence
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    • v.10 no.1
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    • pp.1-14
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    • 2020
  • Antenna selection is a method to enhance the performance of spatial multiplexing multiple-input multiple-output (MIMO) systems, which can achieve the diversity order of the full MIMO systems. Although various selection criteria have been studied in the literature, they should be adjusted to the detection operation implemented at the receiver. In this paper, antenna selection methods that optimize the post-processing signal-to-noise ratio (SNR) and eigenvalue are considered for the lattice reduction (LR)-based receiver. To develop a complexity-efficient antenna selection algorithm, the incremental selection strategy is adopted. Moreover, for improvement of performance, an additional iterative selection method is presented in combination with an incremental strategy.

The Effect of Counterfactual Thinking on Post-purchase Behavior of Retail Management

  • Kim, Young-Ei;Yang, Hoe-Chang
    • Journal of Distribution Science
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    • v.16 no.2
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    • pp.25-33
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    • 2018
  • Purpose - This study focused on the effect of counter-factual thinking on post-purchase behavior producing consumer regret at HMR selection and purchase. We have analyzed the factors that HMR production and distribution businesses should consider because distribution and marketing strategy reflecting consumers' demand. Research design, data, and methodology - For the purpose of carrying out this research, we conducted a direst structured questionnaire to students at 'J' college. A total of 237 valid questionnaires were collected for students and their parents at 'J' university. For the hypothesis test, exploratory factor analysis, t-test, regression and structure equation path analysis were performed. Results - The consumers who often resented HMR purchase did counter-factual thinking on post-purchase behavior were likely to do switching purchases. Counter-factual thinking on post-purchase behavior had a negative influence upon consumer's satisfaction with HMR safety and marketing characteristics. Conclusions - Consumers who had been satisfied to a certain degree might have cognitive dissonance of minor mistakes of HMR product were likely to have downward counter-factual thinking through contrast effects. Therefore, HMR producer and distribution businesses that had production, distribution and marketing strategy to satisfy consumers by raw material, freshness and safety were likely to switch to another product at one time mistake of selection, purchase and use.

Outcomes of Gastrectomy for Gastric Cancer in Patients Aged >80 Years: A Systematic Literature Review and Meta-Analysis

  • Zelalem Chimdesa Merga ;Ji Sung Lee ;Chung-Sik Gong
    • Journal of Gastric Cancer
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    • v.23 no.3
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    • pp.428-450
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    • 2023
  • This meta-analysis examined the surgical management of older patients (>80 years) with gastric cancer, who were often excluded from randomized controlled trials. We analyzed 23 retrospective cohort studies involving 18,372 patients and found that older patients had a higher in-hospital mortality rate (relative risk [RR], 3.23; 95% confidence interval [CI], 1.46-7.17; P<0.01) and more post-operative complications (RR, 1.36; 95% CI, 1.19-1.56; P<0.01) than did younger patients. However, the surgical complications were similar between the two groups. Older patients were more likely to undergo less extensive lymph node dissection and longer hospital stays. Although older patients had statistically significant post-operative medical complications, they were not deprived of surgery for gastric cancer. The comorbidities and potential risks of post-operative complications should be carefully evaluated in older patients, highlighting the importance of careful patient selection. Overall, this meta-analysis provides recommendations for the surgical management of older patients with gastric cancer. Careful patient selection and evaluation of comorbidities should be performed to minimize the risk of post-operative complications in older patients, while recognizing that they should not be deprived of surgery for gastric cancer.

Biocomputational Characterization and Evolutionary Analysis of Bubaline Dicer1 Enzyme

  • Singh, Jasdeep;Mukhopadhyay, Chandra Sekhar;Arora, Jaspreet Singh;Kaur, Simarjeet
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.6
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    • pp.876-887
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    • 2015
  • Dicer, an ribonuclease type III type endonuclease, is the key enzyme involved in biogenesis of microRNAs (miRNAs) and small interfering RNAs (siRNAs), and thus plays a critical role in RNA interference through post transcriptional regulation of gene expression. This enzyme has not been well studied in the Indian water buffalo, an important species known for disease resistance and high milk production. In this study, the primary coding sequence (5,778 bp) of bubaline dicer (GenBank: AB969677.1) was determined and the bubaline Dicer1 biocomputationally characterized to determine the phylogenetic signature among higher eukaryotes. The evolutionary tree revealed that all the transcript variants of Dicer1 belonging to a specific species were within the same node and the sequences belonging to primates, rodents and lagomorphs, avians and reptiles formed independent clusters. The bubaline dicer1 is closely related to that of cattle and other ruminants and significantly divergent from dicer of lower species such as tapeworm, sea urchin and fruit fly. Evolutionary divergence analysis conducted using MEGA6 software indicated that dicer has undergone purifying selection over the time. Seventeen divergent sequences, representing each of the families/taxa were selected to study the specific regions of positive vis-$\grave{a}$-vis negative selection using different models like single likelihood ancestor counting, fixed effects likelihood, and random effects likelihood of Datamonkey server. Comparative analysis of the domain structure revealed that Dicer1 is conserved across mammalian species while variation both in terms of length of Dicer enzyme and presence or absence of domain is evident in the lower organisms.